<?php
/**
 * Created by PhpStorm.
 * User: zhangrongxiang
 * Date: 2018/2/2
 * Time: 下午11:16
 */

$str = "Hello World! Hello PHP";
$pos = mb_strpos( $str, "Hello", 0, mb_internal_encoding() );
echo $pos . PHP_EOL;//0
$pos = mb_strpos( $str, "Hello", 2, mb_internal_encoding() );
echo $pos . PHP_EOL;//13

function mb_str_replace( $haystack, $search, $replace, $offset = 0, $encoding = 'auto' ) {
	$len_sch = mb_strlen( $search, $encoding );
	$len_rep = mb_strlen( $replace, $encoding );
	
	while ( ( $offset = mb_strpos( $haystack, $search, $offset, $encoding ) ) !== false ) {
		$haystack = mb_substr( $haystack, 0, $offset, $encoding )
		            . $replace
		            . mb_substr( $haystack, $offset + $len_sch,
				$le = mb_strlen( $haystack ) - mb_strlen( $search ) + mb_strlen( $replace ),
				$encoding );
		//echo $le.PHP_EOL;
		$offset = $offset + $len_rep;
		if ( $offset > mb_strlen( $haystack, $encoding ) ) {
			break;
		}
	}
	
	return $haystack;
}

$replace = mb_str_replace( "hello world !hello world !hello world !hello world !", "hello", "hi" );
echo $replace . PHP_EOL; //hi world !hi world !hi world !hi world !

//hi PHP !hi PHP !hi PHP !hi PHP !
echo mb_str_replace( $replace, "world", "PHP" ) . PHP_EOL;
echo mb_str_replace( $replace, " ", "-" ) . PHP_EOL;

//PHP是世界上最好的语言😂😂😂😂😂😂
echo mb_str_replace( "PHP是世界上最好的语言😄😄😄😄😄😄", '😄', '😂', 0, mb_internal_encoding() ) . PHP_EOL;
echo mb_str_replace( "112233445566", '22', '00' ) . PHP_EOL;//110033445566
echo mb_str_replace( '😄😄😄😄', '😄', '😫1', 2, mb_internal_encoding() ) . PHP_EOL;
echo mb_str_replace( '1111', '111', '0', 1 ) . PHP_EOL;//10
echo mb_strlen( '😄😄😄😄' ) . PHP_EOL;//4

//代码开发代码
echo mb_str_replace( '软件开发软件', '软件', '代码' ,0,mb_internal_encoding()) . PHP_EOL;
//代码开发  //todo??
echo mb_str_replace( '软件开发软件', '软件', '代码' ) . PHP_EOL;